Cabletron Systems STS16-20R User Manual
27
Switch Overview
SmartStack STS16-20D/STS16-20R Token Ring Switches Installation and User Guide
RI/RO-Like Connection on SmartStack STS16-20R
A UTP RI/RO connection is available on ports 19 and 20 on the SmartStack
STS16-20R Switch.
STS16-20R Switch.
This feature allows the SmartStack STS16-20R to connect to CAU/LAM systems
using the RI/RO connections thus providing a RI/RO-like functionality. This
enables the switch to be easily installed in existing Token Ring networks.
using the RI/RO connections thus providing a RI/RO-like functionality. This
enables the switch to be easily installed in existing Token Ring networks.
A loop-back function has been implemented on these ports so that if the port is
disabled or the switch is powered off there will not be a break in the attached main
ring. This means that attaching a cable from the RI port of a MAU port to one of
the two switch ports in effect joins the primary and the backup ring in a MAU/CAU
main ring system. Connecting the other end of the RI/RO connection to the other
switch port, creates redundant paths because the two switch ports are connected to
the same segment. Therefore, the IEEE Spanning Tree Protocol (STP) must be
enabled
disabled or the switch is powered off there will not be a break in the attached main
ring. This means that attaching a cable from the RI port of a MAU port to one of
the two switch ports in effect joins the primary and the backup ring in a MAU/CAU
main ring system. Connecting the other end of the RI/RO connection to the other
switch port, creates redundant paths because the two switch ports are connected to
the same segment. Therefore, the IEEE Spanning Tree Protocol (STP) must be
enabled
, which will place one port in forward and the other in blocked mode. If
there is a break in the main ring, the STP will place both ports in forward mode, and
all MACs on both segments will be relearned.
all MACs on both segments will be relearned.
If a SmartStack STS16-20R port has been configured to RI/RO mode, it will
automatically sense whether the port has been connected to RI or RO of the MAU.
automatically sense whether the port has been connected to RI or RO of the MAU.
Note:
It is not possible to automatically verify whether a UTP/STP port has been
connected according to the configuration. Any errors, such as attaching port 19 or
20 to a normal MAU port when the SmartStack STS16-20R port has been
configured for RI/RO, will cause a complete disruption of the ring to which the port
is attached. Therefore, be careful when using the RI/RO feature.
20 to a normal MAU port when the SmartStack STS16-20R port has been
configured for RI/RO, will cause a complete disruption of the ring to which the port
is attached. Therefore, be careful when using the RI/RO feature.